Yersinia pseudotuberculosis

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Yersinia pseudotuberculosis
Scientific classification
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Enterobacteriales
Family: Enterobacteriaceae
Genus: Yersinia
Species: Y. pseudotuberculosis
Binomial name
Yersinia pseudotuberculosis
(Pfeiffer 1889)
Smith & Thal 1965

Yersinia pseudotuberculosis is a Gram-negative bacterium that causes Far East scarlet-like fever in humans, who occasionally get infected zoonotically, most often through the food-borne route.[1] Animals are also infected by Y. pseudotuberculosis. The bacterium is urease positive.


Yersinia pseudotuberculosis
Yersinia pestis scanned with electron micrograph.jpg
Yersinia scanned with electron micrograph
Classification and external resources
ICD-10 A04.8, A28.2
DiseasesDB 14237
eMedicine article/226871
MeSH D015012

In animals, Y. pseudotuberculosis can cause tuberculosis-like symptoms, including localized tissue necrosis((No gloss)) and granulomas in the spleen(脾臓(ひぞう)), liver, and lymph(リンパ,リンパ液,血清,痘苗) nodes(節点,【ネットワーク】ノード).

In humans, symptoms of Far East scarlet-like fever are similar to those of infection with Yersinia enterocolitica (fever and right-sided abdominal(腹部) pain), except that the diarrheal component is often absent, which sometimes makes the resulting condition difficult to diagnose. Y. pseudotuberculosis infections can mimic appendicitis(【病名】虫垂炎(いわゆる盲腸炎)), especially in children and younger adults, and, in rare cases, the disease may cause skin complaints (erythema nodosum), joint stiffness and pain (reactive arthritis(関節炎)), or spread of bacteria to the blood (bacteremia).

Far East scarlet-like fever usually becomes apparent five to 10 days after exposure and typically lasts one to three weeks without treatment. In complex cases or those involving immunocompromised patients, antibiotics may be necessary for resolution; ampicillin, aminoglycosides, tetracycline, chloramphenicol, or a cephalosporin may all be effective.

The recently described syndrome "Izumi-fever" has been linked to infection with Y. pseudotuberculosis.[2]

The symptoms of fever and abdominal(腹部) pain mimicking appendicitis(【病名】虫垂炎(いわゆる盲腸炎)) (actually from mesenteric lymphadenitis) [3][4][5] associated with Y. pseudotuberculosis infection are not typical of the diarrhea and vomiting from classical food poisoning incidents. Although Y. pseudotuberculosis is usually only able to colonize hosts by peripheral routes and cause serious disease in immunocompromised individuals, if this bacterium gains access to the blood stream, it has an LD50 comparable to Y. pestis at only 10 CFU.[6]

Relationship to Y. pestis[edit]

Genetically, the pathogen((No gloss)) causing plague, Y. pestis, is very similar to Y. pseudotuberculosis. The plague appears to have evolved from Y. pseudotuberculosis about 1500 to 20,000 years ago.[7]

Virulence factors[edit]

To facilitate attachment, invasion, and colonization((No gloss)) of its host, this bacterium possesses many virulence factors. Superantigens, bacterial adhesions, and the actions of Yops (which are bacterial proteins once thought to be "Yersinia outer membrane(薄膜,膜,皮膜,膜組織) proteins") that are encoded(符合化する) on the "[plasmid] for Yersinia virulence"commonly known as the pYVcause host pathogenesis and allow the bacteria to live parasitically.


The 70-kb pYV is critical to Yersinia's pathogenicity, since it contains many genes known to encode(符合化する) virulence factors and its loss gives avirulence of all Yersinia species.[6] A 26-kb "core region" in the pYV contains the ysc genes, which regulate the expression and secretion(分泌(物,液),隠匿,分泌物) of Yops.[5] Many Ysc proteins also amalgamate to form a type-III secretory apparatus, which secretes many Yops into the host cell cytoplasm((No gloss)) with the assistance of the "translocation apparatus", constructed of YopB and YopD.[8][9] The core region also includes yopN, yopB, yopD, tyeA, lcrG, and lcrV, which also regulate Yops gene expression and help to translocate secretory Yops to the target cell.[5] For example, YopN and TyeA are positioned as a plug on the apparatus so only their conformational change, induced by their interaction with certain host cell membrane(薄膜,膜,皮膜,膜組織) proteins, will cause the unblocking of the secretory pathway.[5][10] Secretion is regulated in this fashion so that proteins are not expelled into the extracellular matrix and elicit an immune response. Since this pathway gives secretion(分泌(物,液),隠匿,分泌物) selectivity, it is a virulence factor.

Effector Yops[edit]

In contrast to the ysc and yop genes listed above, the Yops that act directly on host cells to cause cytopathologic effects – "effector Yops" – are encoded(符合化する) by pYV genes external to this core region.[5] The sole exception is LcrV, which is also known as the "versatile Yop" for its two roles as an effector Yop and as a regulatory Yop.[5] The combined function of these effector Yops permits the bacteria to resist internalization by immune and intestinal cells and to evade the bactericidal actions of neutrophils and macrophages. Inside the bacterium, these Yops are bound by pYV-encoded Sycs (specific Yop chaperones), which prevent premature interaction with other proteins and guide the Yops to a type-III secretory apparatus.[9] In addition to the Syc-Yop complex, Yops are also tagged for type III secretion(分泌(物,液),隠匿,分泌物) either by the first 60nt in their corresponding mRNA transcript or by their corresponding first 20 N-terminal amino acids.[4] LcrV, YopQ, YopE, YopT, YopH, YpkA, YopJ, YopM, and YadA are all secreted by the type-III secretory pathway.[4][5][10] LcrV inhibits neutrophil((No gloss)) chemotaxis and cytokine production, allowing Y. pseudotuberculosis to form large colonies without inducing systemic failure[10] and, with YopQ, contributes to the translocation process by bringing YopB and YopD to the eukaryotic cell membrane(薄膜,膜,皮膜,膜組織) for pore-formation.[4][11] By causing actin filament depolymerisation, YopE, YopT, and YpkA resist endocytosis by intestinal cells and phagocytosis while giving cytotoxic((No gloss)) changes in the host cell. YopT targets Rho GTPase, commonly named "RhoA", and uncouples it from the membrane,(薄膜,膜,皮膜,膜組織) leaving it in an inactive RhoA-GDI (guanine nucleotide((No gloss)) dissociation((No gloss)) inhibitor)-bound((No gloss)) state[12] whereas YopE and YpkA convert Rho proteins to their inactive GDP-bound states by expressing GTPase activity.[10] YpkA also catalyses serine((No gloss)) autophosporylation, so it may have regulatory functions in Yersinia[13] or undermine host cell immune response signal cascades since YpkA is targeted to the cytoplasmic side of the host cell membrane.(薄膜,膜,皮膜,膜組織)[14] YopH acts on host focal adhesion(粘着) sites by dephosphorylating several phosphotyrosine residues on focal adhesion(粘着) kinase (FAK) and the focal adhesion(粘着) proteins paxillin and p130.[15] Since FAK phosphorylation is involved in uptake(摂取) of yersiniae[16] as well as T cell and B cell responses to antigen-binding,((No gloss))[10] YopH elicits antiphagocytic and other anti-immune effects. YopJ, which shares an operon with YpkA, "...interferes with the mitogen-activated protein (MAP) kinase activities of c-Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase",[17] leading to macrophage apoptosis.[4] In addition, YopJ inhibits TNF-α release from many cell types, possibly through an inhibitory(抑制する) action on NF-κB, suppressing inflammation and the immune response.[18] By secretion(分泌(物,液),隠匿,分泌物) through a type III pathway and localization(局所化) in the nucleus by a vesicle-associated, microtubule-dependent method, YopM may alter host cell growth by binding to RSK (ribosomal S6 kinase), which regulates cell cycle regulation genes.[10] Interestingly, YadA has lost its adhesion,(粘着)[19] opsonisation-resisting, phagocytosis-resisting, and respiratory(呼吸の) burst-resisting functions[20][21] in Y. pseudotuberculosis due to a frameshift mutation by a single base-pair deletion((No gloss)) in yadA in comparison to yadA in Y. enterocolitica, yet it still is secreted by type III secretion.(分泌(物,液),隠匿,分泌物)[22] The yop genes, yadA, ylpA, and the virC operon are considered the "Yop regulon" since they are coregulated by pYV-encoded VirF. virF is in turn thermoregulated. At 37 degrees Celsius, chromosomally encoded(符合化する) Ymo, which regulates DNA supercoiling around the virF gene, changes conformation,((No gloss)) allowing for VirF expression, which then up-regulates the Yop regulon.[23]


Y. pseudotuberculosis adheres strongly to intestinal cells via chromosomally encoded(符合化する) proteins[4] so that Yop secretion(分泌(物,液),隠匿,分泌物) may occur, to avoid being removed by peristalsis, and to invade target host cells. A transmembrane protein, Invasin, facilitates these functions by binding to host cell αβ1 integrins.[24] Through this binding, the integrins cluster, thereby activating FAK, and causing a corresponding reorganization(1.再編成,改組,改編,2.【金融】再建,立て直し,再編成) of the cytoskeleton.[4][24] Subsequent internalization of bound bacteria occurs when the actin-depolymerising Yops are not being expressed.[10] The protein encoded(符合化する) on the "attachment invasion locus"((No gloss)) named Ail also bestows attachment and invasive(侵略的な) abilities upon Yersiniae[25] while interfering with the binding of complement on the bacterial surface.[26] To increase binding specificity, the fibrillar pH6 antigen((No gloss)) targets bacteria to target intestinal cells only when thermoinduced.[27]


Certain strains of Yersinia pseudotuberculosis express a superantigenic exotoxin, YPM, or the Y. pseudotuberculosis-derived mitogen, from the chromosomal ypm gene.[28] YPM specifically binds and causes the proliferation of T lymphocytes expressing the Vβ3, Vβ7, Vβ8, Vβ9, Vβ13.1, and Vβ13.2 variable regions [29] with CD4+ T cell preference, although activation(現役編入) of some CD8+ T cells occurs.[3] This T cell expansion can cause splenomegaly coupled with IL-2 and IL-4 overproduction.[30] Since administering anti-TNF-α and anti-IFN-γ monoclonal antibodies neutralizes YPM toxicity in vivo,[28] these cytokines are largely responsible for the damage caused indirectly by the exotoxin. Strains that carry the exotoxin gene are rare in Western countries, where the disease, when at all apparent, manifests itself largely with minor symptoms, whereas more than 95% of strains from Far Eastern countries contain ypm[31] and are correlated(相互に関連がある,相互関係を持たせる) with Izumi fever and Kawasaki disease.[32] Although the superantigen poses the greatest threat to host health, all virulence factors contribute to Y. pseudotuberculosis viability in vivo and define the bacterium’s pathogenic((No gloss)) characteristics. Y. pseudotuberculosis can live extracellularly due to its formidable mechanisms of phagocytosis and opsonisation resistance through the expression of Yops and the type III pathway;[9] yet, by limited pYV action, it can populate host cells, especially macrophages, intracellularly to further evade immune responses and be disseminated((種子など)をまく,(意見など)を広める,ばらまく,広める,散布する,広まる) throughout the body.[33]

PDB 1pm4 EBI.jpg
crystal structure of yersinia pseudotuberculosis-derived mitogen (ypm)
Symbol YpM
Pfam PF09144
InterPro IPR015227
SCOP 1pm4


Yersinia pseudotuberculosis-derived mitogens (YpM) are superantigens, which are able to excessively(過度に) activate T cells by binding to the T cell receptor. Since YpM can activate large numbers of the T cell population, this leads the release of inflammatory cytokines.


Members of this family of Yersinia pseudotuberculosis mitogens adopt a sandwich structure consisting of 9 strands in two beta sheets, in a jelly-roll topology. YpM molecular(分子の) weight is about 14 kDa. Structurally, it is unlike any other superantigen, but is remarkably similar to the tumour((No gloss)) necrosis((No gloss)) factor and viral(ウイルスの,ウイルスによっておこる) capsid proteins. This suggests a possible evolutionary relationship.[34]


Some highly homologous((No gloss)) variants of YPM have been characterized, including YPMa, YPMb, and YPMc.


  1. ^ Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. ISBN 0-8385-8529-9. 
  2. ^ Jani, Asim (2003). "Pseudotuberculosis (Yersina)". Retrieved 2006-03-04. 
  3. ^ a b Carnoy, C., N. Lemaitre, and M. Simonet. 2006. The superantigenic toxin of Yersinia pseudotuberculosis, p.862-871. In J. E. Alouf and M. R. Popoff (ed.), The comprehensive sourcebook of bacterial protein toxins, 3rd ed. Elsevier Ltd., Burlington, MA.
  4. ^ a b c d e f g Robins-Browne, R. and E. Hartland. 2003. Yersinia species, p.323-355. In M. D. Miliotis and J. W. Bier (ed.), International handbook of foodborne pathogens. Marcel Dekker, Inc., New York, NY.
  5. ^ a b c d e f g Lindler, L. 2004. Virulence plasmids of Yersinia: characteristics and comparison, p.423-437. In B. E. Funnel and G. J. Phillips (ed.), Plasmid biology. ASM Press, Washington, DC.
  6. ^ a b Brubaker, R. 1983. The Vwa+ virulence factor of yersiniae: the molecular basis of the attendant nutritional requirement for Ca++. Rev. Infect. Dis. 5:S748-S758.
  7. ^ Achtman, M.; Zurth, K., Morelli, G., Torrea, G., Guiyoule, A., & Carniel; E. (23 November 1999). "Yersinia pestis, the cause of plague, is a recently emerged clone of Yersinia pseudotuberculosis". Proceedings of the National Academy of Sciences 96 (24): 14043–14048. doi:10.1073/pnas.96.24.14043. PMC 24187. PMID 10570195. Retrieved 21 March 2013. 
  8. ^ Iriarte, M. and G. Cornelis. 1999. Identification of SycN, YscX, and TscY, three new elements of the Yersinia yop virulon. J. Bacteriol. 181:675-680.
  9. ^ a b c Cornelis, G., A. Boland, A. Boyd, C. Geuijen, M. Iriarte, C. Neyt, M.-P. Sory, and I. Stainer. 1998. The virulence of Yersinia, an antihost genome. Microbiol. Mol. Biol. Rev. 62:1315-1352.
  10. ^ a b c d e f g Lee, V., C. Tam, and O. Schneewind. 2000. LcrV, a substrate for Yersinia enterocolitica type III secretion, is required for toxin targeting into the cytosol of HeLa cells. J. Biol. Chem. 275:36869-36875.
  11. ^ Zumbihl, R., M. Aeptelbacher, A. Andor, C. Jacobi, K. Ruckdeschel, B. Rouot, and J. Heesemann. 1999. The cytotoxin YopT of Yersinia enterocolitica induces modification and cellular redistribution of the small GTP-binding protein RhoA. J. Biol. Chem. 274:29289-29293.
  12. ^ Persson, C., N. Carballeira, H. Wolf-Watz, M. Fallman. 1997. The PTPase YopH inhibits uptake of Yersinia, tyrosine phosphorylation of p130Cas and FAK, and the associated accumulation of these proteins in peripheral focal adhesions. EMBO J. 16:2307-2318.
  13. ^ Haokansson, S., E. Galyov, R. Rosqvist, H. Wolf-Watz. 1996. The Yersinia YpkA Ser/Thr kinase is translocated and subsequently targeted to the inner surface of the HeLa plasma membrane. Mol. Microbiol. 20:593-603.
  14. ^ Ruckdeshel, K., J. Machold, A. Roggenkamp, S. Schubert, J. Pierre, R. Zumbihl, J. Liautard, J. Heesemann, and B. Rouot. 1997. Yersinia eneterocolitica promotes deactivation of macrophage mitogen-activated protein kinases extracellular signal-related kinase-1/2, p38, and c-Jun NH2-terminal kinase. Correlation with its inhibitory effect on tumor necrosis factor-α production. J. Biol. Chem. 272:15920-15927.
  15. ^ Alrutz, M. and R. Isberg. 1998. Involvement of focal adhesion kinase in invasion-mediated uptake. Proc. Natl. Acad. Sci. 95:13658-13663.
  16. ^ Galyov, E., S. Hakansson, A. Forsberg, and H. Wolf-Watz. 1993. A secreted protein kinase of Yersinia pseudotuberculosis is an indispensable virulence determinant. Nature 361:730-732.
  17. ^ Boland, A. and G. Cornelis. 1998. Role of YopP in suppression of tumor necrosis factor alpha release by macrophages during Yersinia infection. Infect. Immun. 66:1878-1884.
  18. ^ Skurnik, M., Y. el Tahir, M. Saarinen, S. Jalkanen, and P. Toivanen. 1994. YadA mediates specific binding of enteropathogenic Yersinia enterocolitica to human intestinal submucosa. Infect. Immun. 62:1252-1261.
  19. ^ China, B., M. Sory, B. N’Guyen, M. de Bruyere, and G. Cornelis. 1993. Role of the YadA protein in prevention of opsonisation of Yersinia enterocolitica by C3b molecules. Infect. Immun. 61:3129-3136.
  20. ^ China, B., B. N’Guyen, M. de Bruyere, and G. Cornelis. 1994. Role of YadA in resistance of Yersinia enterocolitica to phagocytosis by human polymorphonuclear leukocytes. Infect. Immun. 62:1275-1281.
  21. ^ Han, Y. and V. Miller. 1997. Reevaluation of the virulence phenotype of the inv yadA double mutants of Yersinia pseudotuberculosis. Infect. Immun. 65:327-330.
  22. ^ Cornelis, G., C. Sluiters, I. Delor, D. Geib, K. Kaniga, C. Lambert de Rouvroit, M.-P. Sory, J.-C. Vanooteghem, and T. Michiels. 1991. ymoA, a Yersinia enterocolitica chromosomal gene modulating the expression of virulence functions. Mol Microbiol. 5:1023-1034.
  23. ^ Isberg, R. and G. Van Nhieu. 1994. Two mammalian cell internalization strategies used by pathogenic bacteria. Annu. Rev. Genet. 28:395-422.
  24. ^ a b Miller, V. 1992. Yersinia invasion genes and their products. ASM News 58:26-33.
  25. ^ Bliska, J. and S. Falkow. 1992. Bacterial resistance to complement killing mediated by the Ail protein of Yersinia enterocolitica. Proc. Natl. Acad. Sci. 89:3561-3565.
  26. ^ Lindler, L. and B. Tall. 1993. Yersinia pestis pH 6 antigen forms fimbriae and is induced by intracellular association with macrophages. Mol. Microbiol. 8:311-324.
  27. ^ Miyoshi-Akiyama, T., W. Fujimaki, X. Yan, J. Yagi, K. Imanishi, H. Kato, K. Tomonari, and T. Uchiyama. 1997. Identification of murine T cells reactive with the bacterial superantigen Yersinia pseudotuberculosis-derived mitogen (YPM) and factors involved in YPM-induced toxicity in mice. Microbiol. Immunol. 41:345-352.
  28. ^ a b Uchiyama, T., T. Miyoshi-Akiyama, H. Kato, W. Fujimaki, K. Imanishi, and X. Yan. 1993. Superantigenic properties of a novel mitogenic substance produced by Yersinia pseudotuberculosis isolated from patients manifesting acute and systemic symptoms. J. Immunol. 151:4407-4413.
  29. ^ Carnoy, C., C. Loiez, C. Faveeuw, C. Grangette, P. Desreumaux, and M. Simonet. 2003. Impact of the Yersinia pseudotuberculosis-derived mitogen (YPM) on the murine immune system. Adv. Exp. Med. Biol. 529:133-135.
  30. ^ Yoshino, K., T. Ramamurthy, G. Nair, H. Fukushima, Y. Ohtomo, N. Takeda, S. Kaneko, and T. Takeda. 1995. Geographical heterogeneity between Far East and Europe in prevalence of ypm gene encoding the novel superantigen among Yersinia pseudotuberculosis strains. J. Clin. Microbiol. 33:3356-3358.
  31. ^ Fukushima, H., Y. Matsuda, R. Seki, M. Tsubokura, N. Takeda, F. Shubin, I. Paik, and X. Zheng. 2001. Geographical heterogeneity between Far Eastern and Western countries in prevalence of the virulence plasmid, the superantigen Yersinia pseudotuberculosis-derived mitogen, and the high-pathogenicity island among Yersinia pseudotuberculosis strains. J. Clin. Microbiol. 39:3541-3547.
  32. ^ Nikolova, S., H. Najdenski, D. Wesselinova, A. Vesselinova, D. Kazatchca, and P. Neikov. 1997. Immunological and electronmicroscopic studies in pigs infected with Yersinia enterocolitica O:3. Zentralbl. Bakteriol. 286:503-510.
  33. ^ Smith, M. 1992. Destruction of bacteria on fresh meat by hot water. Epidemiol. Infect. 109:491-496.
  34. ^ Donadini R, Liew CW, Kwan AH, Mackay JP, Fields BA (January 2004). "Crystal and solution structures of a superantigen from Yersinia pseudotuberculosis reveal a jelly-roll fold". Structure 12 (1): 145–56. doi:10.1016/j.str.2003.12.002. PMID 14725774. 

This article incorporates text from the public domain Pfam and InterPro IPR015227

External links[edit]